1. Field of the Invention
This invention relates in general to the field of pneumatic automatic fastener feeding machines and in particular to the field of automatic fastener feeding machines having a pivoting track arrangement in combination with a racheting supply hopper.
2. Description of the Prior Art
An automatic fastener feeding machine is the terminology which is commonly applied to a machine which arranges fasteners, such as screws, rivets, headed pins, or the like, from a bulk, loose form into an arrangement whereby the fasteners are aligned in a single column on a track arrangement and then individually delivered by an escapement mechanism to an air driven or electric applicator such as a screw driver. The screw driver is then utilized to drive a single fastener through a hole within one component in order to fasten the one component to another. Further, it is common practice in such prior art automatic fastener feeding machines to utilize a pneumatic source, such as air in combination with electrical energy, to operate or drive various mechanisms within the apparatus. The purpose of such automatic fastener feeding machines is, of course, to speed up production by providing automatic delivery of a fastener to a screw driver which both holds the fastener in place and screws the same into position. The net result being rapid assembly of various components using fasteners.
Since speed of production is the main objective of such machines, any portion of the machine which tends to jam or malfunction in any manner results in a work stoppage or delay which is contrary to such main objective. Each operation performed upon a fastener within the automatic feeding machine from its bulk supply disposition to its fastener disposition and any point therebetween must necessarily occur in a serial mode whereby one step follows the other. Any one step, therefore, if it is not accomplished properly, can delay operations or even cause a complete shut down of the machine and production. In today's modern factories, any unnecessary delay or production shutdown due to malfunctioning of a machine, must be avoided at all reasonable cost.
Moreover, industry requires that fastener feeding machines be adaptable to work with fasteners which are mass produced. Mass production of fasteners generally involves large variations or tolerances for a given characteristic of the fastener such as its head height, head diameter, shank diameter, shank length, etc., than corresponding individualized custom machined fasteners. Since automatic fastener feeding machines must accommodate such mass produced fasteners, the handling of such fasteners as well as the operations performed on the fasteners by an automatic fastener feeding machine requires even further design constraints on such machines. As a result, the prior art automatic fastener feeding machines tend to be relatively complicated and require an undue amount of precision manufacturing in order to produce long lasting and reliable fastener feeding machines. Unfortunately, such design constraints also, have in the past, resulted in relatively expensive automatic fastener feeding machines which high cost, of necessity, tends to prevent usage in production plants where there is not a great profit gain or cost reduction by utilizing the automatic fastener feeding machines.
It is a practice in the prior art to utilize electrical energy to drive a motor which rotates a supply hopper containing the fasteners or vibrates the fasteners so they travel along an uphill spiral through sorting and orienting gates. From the spiral or the hopper, the fasteners travel along a track under the influence of gravity which may be assisted by air or electric motive power. Then, air is customarily used in order to operate an escape mechanism whereby a single fastener is delivered from the automatic fastener feeding apparatus to a pneumatically- or electrically-operated fastener driver. The use of these two types of energy sources, that is, electricity and air, while allowing the use of historically reliable components such as electric motors and air cylinders, complicates the automatic fastener feeding machine by requiring a work station to have both types of energy sources available. Accordingly, it is a primary objective of the present invention to provide reliable automatic fastener feeding apparatus which utilizes only a pneumatic source as the source of energy for the apparatus.
In the prior art, the track arrangement is one whereby a plurality of screws or other like headed fasteners are delivered in a single row and such that as one fastener is utilized, the other fasteners move down the track making room for a new fastener to be added to the line of fasteners on the track. In this art, two types of energy sources have been utilized to move the fasteners along the track, to wit: gravity and/or vibrations which when applied to a track arrangement keep the fasteners constantly in motion and prevents snagging or binding of the fasteners upon each other. Obviously, it is preferable that only a gravity feed type of arrangement be utilized for automatic fastener feeding machines and thereby eliminate another energy supply and any complications associated with the mechanism thereof. This, therefore, comprises a main objective of the present invention.
In conjunction with the use of gravity feeding of the fasteners along a track mechanism, and the utilization of solely a pneumatic source of energy, further objectives of the present invention involve providing an automatic fastener feeding machine which is yet also simple in construction and therefore inexpensive and yet highly reliable.
The above-stated objects as well as other objects which, although not specifically stated, but are intended to be included within the scope of the present invention, are accomplished by the present invention and will become apparent from the hereinafter set forth Detailed Description of the Invention, Drawings, and the Claims appended herewith.